سنن ابن ماجه

It was narrated that ‘Aishah said: “The Messenger of Allah (ﷺ) entered the house and saw a piece of bread that had been thrown (on the floor). He picked it up, wiped it and ate it, and said: ‘O ‘Aishah, show honor to the precious (i.e., food), for is the blessing of food departs from people, it never comes back.’”